MySQL - 是否可以在不使用 UNION 的情况下组合两个查询？

Question

我有 2 个具有不同结果集的 SQL 查询。虽然它们都来自同一个表，但第二个查询确实依赖于另一个表。如何在不使用 UNION 的情况下组合这两个查询？

这是我的查询。

SELECT tmp.id, tmp.title , tmp.description, asst.smallUrl, b1.paramVal as duration, b2.paramVal as clips, asst.fileUrl as video
FROM listDb.baseData tmp
INNER JOIN listDb.tag tag ON tag.baseDataId= tmp.id and tag.tag = 'service app' and tag.status = "active"
INNER JOIN listDb.baseParam b0 ON b0.baseDataId= tmp.id
and ((b0.paramName = "role"
and (b0.paramVal = "public"))
or ((select count(*) from listDb.baseParam temp
where temp.baseDataId= tmp.id and paramName = "role" )=0))
or (b0.paramName = "role" and b0.paramVal = "public" and tmp.owner = 27)
LEFT JOIN listDb.baseParam b1 ON b1.baseDataId= tmp.id and b1.paramName="duration" and b1.status = "active"
LEFT JOIN listDb.baseParam b2 ON b2.baseDataId= tmp.id and b2.paramName=" itemCount" and b2.status = "active"
LEFT JOIN listDb.baseParam b3 ON b3.baseDataId= tmp.id and b3.paramName="previewUrl" and b3.status = "active"
LEFT JOIN assetDb.baseData asst ON asst.id = b3.paramVal and asst.status = "active"
WHERE tmp.status = "active" and tmp.application = "template" and tmp.role = "public"

UNION

SELECT tmp.id, tmp.title , tmp.description, asst.smallUrl, b1.paramVal as duration, b2.paramVal as clips, asst.fileUrl as video
FROM listDb.baseData tmp
INNER JOIN listDb.tag tag ON tag.baseDataId= tmp.id and tag.tag = 'service app' and tag.status = "active"
INNER JOIN listDb.baseParam b0 ON b0.baseDataId= tmp.id
and ((b0.paramName = "role"
and (b0.paramVal = "private" or b0.paramVal = "" and b0.paramVal != "public"))
or ((select count(*) from listDb.baseParam temp
where temp.baseDataId= tmp.id and paramName = "role" )=0))
or (b0.paramName = "role" and b0.paramVal = "public" and tmp.owner = 27)
LEFT JOIN listDb.baseParam b1 ON b1.baseDataId= tmp.id and b1.paramName="duration" and b1.status = "active"
LEFT JOIN listDb.baseParam b2 ON b2.baseDataId= tmp.id and b2.paramName="itemCount" and b2.status = "active"
LEFT JOIN listDb.baseParam b3 ON b3.baseDataId= tmp.id and b3.paramName="previewUrl" and b3.status = "active"
LEFT JOIN assetDb.baseData asst ON asst.id = b3.paramVal and asst.status = "active"
INNER JOIN listDb.checkRestricted cr ON cr.baseDataId= tmp.id  and cr.status = "active"  and cr.owner = 27
WHERE tmp.status = "active" and tmp.application = "template" and tmp.role = "private"

Answer 1

您好，您可以在不使用联合的情况下尝试这些查询

SELECT tmp.id, tmp.title, tmp.description, asst.smallUrl, b1.paramVal AS duration, b2.paramVal AS clips, asst.fileUrl AS video
FROM listDb.baseData tmp INNER JOIN listDb.tag tag ON tag.baseDataId= tmp.id AND tag.tag = 'service app' AND tag.status = "active"
INNER JOIN listDb.baseParam b0 ON b0.baseDataId= tmp.id AND ((b0.paramName = "role" AND ((b0.paramVal = "public") OR (b0.paramVal = "private" OR b0.paramVal = ""))) OR ((
SELECT COUNT(*) FROM listDb.baseParam temp WHERE temp.baseDataId= tmp.id AND paramName = "role")=0)) OR (b0.paramName = "role" AND b0.paramVal = "public" AND tmp.owner = 27)
LEFT JOIN listDb.baseParam b1 ON b1.baseDataId= tmp.id AND b1.paramName="duration" AND b1.status = "active"
LEFT JOIN listDb.baseParam b2 ON b2.baseDataId= tmp.id AND b2.paramName=" itemCount" AND b2.status = "active"
LEFT JOIN listDb.baseParam b3 ON b3.baseDataId= tmp.id AND b3.paramName="previewUrl" AND b3.status = "active"
LEFT JOIN assetDb.baseData asst ON asst.id = b3.paramVal AND asst.status = "active"
WHERE tmp.status = "active" AND tmp.application = "template" AND (tmp.role = "public" OR tmp.role = "private") group by tmp.id

Answer 2

所以，查询之间的区别是：

• 第一个返回b0.paramVal = "public"public "data"
• 第二个 - b0.paramVal = "private" or b0.paramVal = "" private 或等于 private 并检查限制（checkRestricted table）

逻辑上是：

(b0.paramVal = "public")
OR (b0.paramVal in ("private", "") AND EXISTS(...listDb.checkRestricted)

完整来源：

SELECT
  tmp.id, tmp.title , tmp.description, asst.smallUrl,
  b1.paramVal as duration, b2.paramVal as clips, asst.fileUrl as video
FROM listDb.baseData tmp
INNER JOIN listDb.tag tag
  ON tag.baseDataId= tmp.id and tag.tag = 'service app' and tag.status = "active"
INNER JOIN listDb.baseParam b0
  ON b0.baseDataId= tmp.id
  AND
  (
    b0.paramName = "role"
    OR 
    (
      NOT EXISTS(select 1 from listDb.baseParam temp
        where temp.baseDataId= tmp.id and paramName = "role" )                 ---<<< does this actually mean LEFT JOIN to listDb.baseParam b0 ???
    )
  )
  or (b0.paramName = "role" and b0.paramVal = "public" and tmp.owner = 27)   ---<<< this is very strange in join
LEFT JOIN listDb.baseParam b1
  ON b1.baseDataId= tmp.id and b1.paramName="duration" and b1.status = "active"
LEFT JOIN listDb.baseParam b2
  ON b2.baseDataId= tmp.id and b2.paramName=" itemCount" and b2.status = "active"
LEFT JOIN listDb.baseParam b3
  ON b3.baseDataId= tmp.id and b3.paramName="previewUrl" and b3.status = "active"
LEFT JOIN assetDb.baseData asst
  ON asst.id = b3.paramVal and asst.status = "active"
WHERE tmp.status = "active"
  and tmp.application = "template"
  /* changes to filter (some alterations might be performed if there must be LEFT JOIN to baseparam0 */
  and tmp.role in ("public", "private")
  and (b0.paramVal = "public"
    OR b0.paramVal in ("private", "")
      AND EXISTS(SELECT 1 FROM listDb.checkRestricted cr
        WHERE cr.baseDataId= tmp.id and cr.status = "active"  and cr.owner = 27)
  )